My scenario is this: I have a 36V golf cart which has six 6V FLA batteries in series. I have a large 36V 21A charger but it is too heavy and awkward to take with me in the cart. Outside the clubhouse, they have courtesy outlets where members can charge their carts for free. For fear of damaging the large 36V 21A charger, I leave it at home. However, I have some small and very light 12V chargers that I sometimes use at home to charge the 36V bank without breaking any series connections. So that tells me they have electrical isolation from each other since they "float" relative to a common ground. For example, imagine the batteries are numbered 1 thru 6. The negative of charger 1 will connect to the negative of battery 2 and the positive of charger 2 will connect to the positive of battery 3 but the negative of battery 2 and the positive of battery 3 are jumpered together in the 36V string.

So of course I can just continue charging the batteries this way by just bringing the chargers with me to the golf course and connecting them this way (3 chargers connected to 3 subbanks simultaneously), however I was wondering what might happen if instead of connecting them as previous described, what might happen if I series connect the chargers into one 36V charger and then charge the golf cart bank with only 2 connection points? Assuming it will even work, would there be any advantage to doing that? To me it seems like a recipe for problems. Would it suffice just to preset the chargers in the same mode and then fire them all up simultaneously? For example, set them all to 12A AGM mode.


closed as off-topic by Dmitry Grigoryev, PeterJ, Daniel Grillo, laptop2d, Vladimir Cravero Sep 21 '16 at 20:27

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    \$\begingroup\$ They can't reliably detect the cell voltages and control their charging algorithms this way. \$\endgroup\$ – Brian Drummond Sep 21 '16 at 11:01

Better chargers reduce the current when the battery is almost full. But when three chargers are connected in series, the reduction of loading current may occur at different time. If one charger operates with reduced current and the others with full current, the chargers or the batteries may be damaged. Without knowing the chargers it can't be predicted what will happen when the chargers are connected in series.

But in my opinion, a real sportsmen would walk the full golf course instead of using a golf cart.

  • \$\begingroup\$ It seems to me that when any 3 chargers are put in series, the maximum current flow will be dictated by the charger with the greatest current restriction. For example, lets suppose you put 3 identical chargers in 3 different modes, one in 2A mode, one in 8A mode, and one in 12A mode. It seems the maximum current flow should be 2A. However what "should" happen and what actually happens could be drastically different in this non-typical application which I am somewhat afraid to try for fear of damaging the three Schumacher SC-1200A chargers. I use my legs a lot at work so I prefer a cart. \$\endgroup\$ – David Sep 21 '16 at 11:25
  • \$\begingroup\$ +1 for the humorous (sarcastic?) note... \$\endgroup\$ – dim Sep 21 '16 at 14:20

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